/* Copyright  2009
   @Author
   Richard Changde Yin            e-mail yinchangde@hotmail.com

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
   
/**
 * @filename: virtual_column_info.h
 */ 

#ifndef ___VIRTUAL_COLUMN_INFO_H__
#define ___VIRTUAL_COLUMN_INFO_H__

#include <definitions.h>
#include <sql_alloc.h>
#include <lex_string.h>

class Item;

class virtual_column_info: public Sql_alloc
{
public:
  Item *expr_item     ;
  
  LEX_STRING expr_str ;
  
  Item *item_free_list;

  virtual_column_info()
                      : expr_item(0), 
                        item_free_list(0),
                        field_type(COLLAPSAR_TYPE_VIRTUAL),
                        is_stored  (false), 
                        data_inited(false)
  {
    expr_str.str= NULL;
    expr_str.length= 0;
  };
  ~virtual_column_info() {}
  enum_field_types get_real_type();
  void set_field_type(enum_field_types fld_type);
  bool get_field_stored();
  void set_field_stored(bool stored);

private:
  /*
    The following data is only updated by the parser and read
    when a Create_field object is created/initialized.
  */
  enum_field_types field_type;   /* Real field type*/
  
  bool is_stored;                /* Indication that the field is
                                 phisically stored in the database*/
  /*
    This flag is used to prevent other applications from
    reading and using incorrect data.
  */
  bool data_inited;
};

#endif /* ___VIRTUAL_COLUMN_INFO_H__ */
